The invention relates to an infinitely variable traction roller transmission in which power is transmitted through traction rollers pivotally supported in a housing between toric input and output discs.
In such transmissions, the traction rollers are mounted on support structures which, when pivoted, cause engagement of the traction rollers with the toric discs in circles of varying diameters depending on the desired transmission ratio. The pivotal traction roller support structures are so mounted that they can be moved axially for initiating a change in the transmission ratio. This is accomplished for example by flexible tension sheets as shown in U.S. Pat. No. 4,086,820 which issued May 2, 1978 to Charles E. Kraus.
However, the forces applied to the traction rollers and, through the traction roller support structure, to the tension sheets are substantial and, consequently require support structure of great strength together with adequate pivot bearings therefor. Also, the transmission is not always free of vibrations and these vibrations are transmitted from the traction rollers to the traction roller support structures and their bearings and finally to the transmission housing.
Also, hydraulic support arrangements are known for supporting the traction rollers which arrangements reduce the bearing loads.